Conventionally, an electrocardiogram is widely used as a heart disease diagnostic index. The electrocardiogram is a signal waveform obtained by detecting the electrical activity of the heart on the body surface, and various kinds of information concerning the heart activity can be obtained by analyzing the electrocardiogram.
Recently, information such as the late potential (LP) or QT dispersion obtained from the electrocardiogram is considered as useful as an index for predicting the occurrence of fatal arrhythmia, and an apparatus which obtains these values from the electrocardiogram is also proposed (see Japanese Patent Laid-Open No. 2002-224068).
Conventionally, however, the indices such as the LP and QT dispersion are individually measured, and no means for comprehensively evaluating the two indices has been provided. Also, although the heart is a three-dimensional organ, no means for intuitively evaluating the distributions and temporal changes of the index values has been provided.